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I am noticing the car is running rich from the smell it is making and the fact that you have to change your clothes if you stand in the garage for 5 seconds with the car started.
Engine is pretty stock, ECM is also stock (had a jet chip which I have removed). I have blank EEPROMs which I intend to start programming but this is besides my question for now.
When I bought the car I immediately started to dismantle it so I cannot say if the issue was there before or not. One of the parts that I changed as it was all rusted up was the Oxygen sensor. I have Edelbrock Shorty headers and the O2 sensor is on the driver's side bank.
When I bought the new sensor from Rockauto it had a p/n AFS 21 (AC DELCO). The old one was a lot shorter than the new one.
Question is, Is the AFS21 good for my car? Maybe it is the cause for running rich?
Was the AFS21 listed for your application? Narrow band (one wire) O2 sensors are dumb. Very dumb. Pretty much any early one wire O2 will interchange with another. Back in the day, the parts stores had 'universal' O2 sensors with a crimp terminal instead of the exact application specific connector. The idea was, a store could have one O2 sensor on the shelf for many applications, and you just reuse your connector and a bit of the wire from your old sensor.
Even if the O2 sensor is unplugged, I doubt you're going to run rich enough to stink up a reasonably well ventilated garage. I'd be looking at things like the CTS, or injectors long before the O2. Especially since the O2 doesn't really come into play until the engine has warmed up and entered closed-loop.
Yes it was in the application for my car. I was suspecting it as physically it was different from the other. I am assuming that if CTS was at fault I would see it through the obd scanner correct?
Injectors are a bit hard to diagnose without taking them off I think.
You can do a pressure leak down with a fuel pressure gauge. It’s normal for blead down to happen after about 10 min. If it’s happening right away a injector or injectors are leaking. The cts can be ohmed for the approximate temp reading or if you have a code 15 it’s more than likely defective.
Bust out the DVOM and set it to ohms. Check the resistance between the two pins of the fuel injector. Do all 8, any that are way off from matching are bad. It's not a foolproof test, an injector can ohm out fine, and still be faulty, but it's something.
I remember I tested them before I assembled the whole inlet and all were within range (forgot the actual range).
I guess if there is a mechanical issue with leaks the resistance is still going to be the same.
Have to check that. Didn’t have time to try out these things before dismantling everything. I am using tuner pro rt I guess I can check if it switching to closed loop
Something interesting. Am going through various forums and looks like leaky injectors lead to longer startup when hot. Mine needs to crank for longer than when it is cold to start.
Something interesting. Am going through various forums and looks like leaky injectors lead to longer startup when hot. Mine needs to crank for longer than when it is cold to start.
True. Leaky injectors or leaking fuel pressure regulator will do that.
A couple other conditions can also cause it but is less common.
Doing my the tests right now. Fuel pressure with engine off is at 36psi. Tester connected to check valve on fuel rail. (Didn’t pinch in and out hoses.) so test includes fuel pump check valve and regulator.
Small update.
Checked timing and put it to 6 degrees as it was around 4.
Connected a wideband to drivers side exhaust outlet(not sure how accurate it will be) and the readings on my LM2 are 1.1 - 1.2 lambda.....
Now this suggests a lean mixture not rich correct? Not an expert on this but would a lean engine smell?
Higher than 1.0 lambda is lean . Lean your run hotter.
Your ecm might be over compensating for a lean condition.
You can use a infrared temp gun and aim at the exhaust ports to see if you have any higher than other cylinder temps to narrow down specific cylinders.
01-19-2018, 09:18 AM
